I have seen Coppercoat, or Copperpoxy, apparently work one year and fail the next. Perhaps the brand is an important difference but even then, sometimes the concept
seems to work and sometimes not. You may notice it has not taken the market by storm, it/they keep getting mixed reviews
And of course if there was a cheap
and certain way to make your own bottom paint
at low cost, sailors would be doing that en masse as well.
So don't kick yourself too hard for using the "wrong" solution, depending on product and local waters and how warm it is one year or how much current
you are in, nothing works all the time. At any price
Except perhaps TBT, which is considered an illegal weapon of mass destruction by most of the world these days. If there is no sea life left within ten miles of Trinidad, we'll know that's true.